As illustrated in FIG. 5, an associated power supply controller is connected to a solar cell 51, a battery 52, and a load 53, and includes (a plurality of) shunt circuits 54, a driver circuit 55, a charging circuit 56, and a discharging circuit 57.
In the power supply controller, an output voltage (bus voltage) of the solar cell 51 is stabilized by the shunt circuit 54 to be supplied to the load 53, and supplied to the charging circuit 56 to charge the battery 52. In order to realize constant current and constant voltage control, the charging circuit 56 includes a switching regulator (battery charge regulator (BCR)).
The operation of the shunt circuit 54 and the charging circuit 56 is controlled by the driver circuit 55 having a redundant circuit structure with high failure resistance. When the output power of the solar cell 51 exceeds load power and then a voltage of a capacitor bank (which is not shown and connected in parallel with load) increases, the driver circuit 55 first causes the charging circuit 56 to be turned ON to charge the battery 52 with excess power. When the excess power increases, the driver circuit 55 causes the shunt circuit 54 to be tuned ON to consume the excess power (by short circuit). When the output power of the solar cell 51 is smaller than the load power, power is supplied from the battery 52 to the load 53 through the discharging circuit 57 (for example, discharge diode).
The power supply controller illustrated in FIG. 5 is of a type frequently used for mainly a low-earth orbit satellite having a large charging current (see Patent Document 1).
There is another associated power supply controller as illustrated in FIG. 6. The power supply controller illustrated in FIG. 6 is connected to not only the solar cell 51, the battery 52, and the load 53 but also a solar cell (charge array) 61 for only charging and includes a charging circuit 62 having a simple switch instead of the charging circuit 56 illustrated in FIG. 5.
The battery 52 is charged by the solar cell 61 for only charging through the charging circuit 62. When the battery 52 is fully charged and the charging circuit 62 is turned OFF, power from the solar cell 61 may be supplied to the load 53.
The power supply controller illustrated in FIG. 6 is of a type frequently used for mainly a geostationary orbit satellite having a small charging current (see Patent Document 1).
In any of the power supply controllers described above, the plurality of shunt circuits are controlled by the single driver circuit 55. There is a power supply controller in which a plurality of shunt circuits are separately controlled by respective driver circuits (see, for example, Patent Document 2).
Further, there is a power supply controller in which a portion of a solar cell (array) for supplying power to a load is also used to charge a battery (see, for example, Patent Document 3).
Patent Document 1: Japanese Unexamined Patent Application Publication (JP-A) No. 2000-134824
Patent Document 2: Japanese Unexamined Patent Application Publication (JP-A) No. 2005-71244
Patent Document 3: Japanese Unexamined Patent Application Publication (JP-A) No. Sho 60-13442